property DisplayMode: TPdfDisplayMode;
Layout mode: single page, continuous, two-page, two-page continuous, with or without cover.
Maps to the PDF /PageLayout hint when reading, but is set independently by the view.
All TPdfView display properties trigger a repaint when assigned; you can change several in sequence without flicker because the redraw is coalesced into a single invalidation.
Active := True.PdfView1.Pdf at runtime, re-apply any view-only settings — the new TPdf has its own state.
begin
PdfView1.DisplayMode := {value};
PdfView1.Active := True;
end;